Original articles
Accuracy of subacromial injection: Anterolateral versus posterior approach

https://doi.org/10.1016/j.jse.2004.06.012Get rights and content

Subacromial bursa injection is commonly performed via an anterolateral or posterior approach. No study has compared the accuracy rates of these approaches. Twenty cadaveric shoulders were injected with radiocontrast in the subacromial bursa via an anterolateral approach and twenty via a posterior approach. Ten shoulders were injected with methylene blue via each technique for dissection. The anterolateral approach was accurate by fluoroscopy in 18 shoulders (90%), but dissection of 10 shoulders revealed successful injection in only 6 (60%). The posterior approach was judged to be successful in 16 shoulders (80%), and dissection of 10 shoulders confirmed 8 injections (80%) were accurate. There was no significant difference in the accuracy by fluoroscopy (P = .38) or dissection (P = .33). The accuracy rates of the anterolateral and posterior approaches to subacromial bursa injections are not significantly different. The anterolateral approach may place injected material medial to the medial bursal boundary, and fluoroscopy may not accurately assess this placement.

Section snippets

Materials and methods

Ten pairs of fresh-frozen cadaveric shoulders (mean age, 73.6 years; age range, 52–90 years) were thawed to room temperature until soft tissues were compliant and mounted in an upright position, clamped at the medial scapula. Each shoulder was injected with 2 mL of radiographic contrast in the subacromial space via anterolateral and posterior approaches by use of a 21-gauge, 1.5-inch (3.8-cm) needle, with fluoroscopic evaluation after each technique. Each shoulder was thus injected twice, once

Anterolateral approach

Subjective grading (Table I) for the anterolateral approach consisted of a grade 3 for 15 injections, grade 2 for 3 injections, and grade 1 for 2 injections. Of the 15 grade 3 injections (confident of accuracy), 12 (80%) were accurate on dissection. The other 3 injections that had been given a grade of 3 were inaccurate, as a result of placement of the injected material medial to the medial boundary of the bursa. Of the 3 injections given a grade of 2, 2 were accurate (67%). Of the two

Discussion

Accuracy of subacromial injection was comparable whether the anterolateral approach (60% accuracy) or posterior approach (80% accuracy) was used, by use of dissection as the gold standard for evaluation. Power did not reach .80, and over 100 specimens would have been required to meet this threshold. The anterolateral accuracy rate is slightly less than that in 2 recent studies, 7, 9 which demonstrated rates of 70% to 83% via the anterolateral approach, and is higher than the rate of 29%

References (9)

There are more references available in the full text version of this article.

Cited by (0)

View full text